Single dose cathartics, i.e, a carthatic given as a single dose, is often osmotic cathartics such as sacharide, sorbitol or saline cathartics like sodium and magnesium salts.
Cathartics are mostly combined with activated charcoal.
Carthatics are recommended for potentially toxic doses of products that are absorbed slowly (e.g slow release preparations or poisons and drugs that inhibit gastric motility)
Carthatics should be avoided in the following situations:
Ingestion of corrosive substances (strong acids and bases, paraquat, bleaches)
Absent bowel sound
Presence of perforation
Avoid magnesium salts in the presence of renal failure
Presence of diarrhoea
Hypotension, hypovolemia, electrolyte imbalance
Less than 1yr old or in the very old